Model Behaviour
by Karanguni
Summary: Allow me to define the world "office-mate" for you: it's a noun. Not a verb.  KakaIru


'Yo,' Shiranui-san said to Iruka on his first day. 'Call me Genma. This is your desk, this is your computer, this is your free and tasteful coffee mug that happens not to be in any of the colours that everyone else in the office uses, and welcome to hell for the next however long you last.' And then Shiranui-call-me-Genma shoved a navy blue mug into Iruka's hand and patted Iruka so hard on the shoulder that Iruka was pitched involuntarily into his new (ergonomic and leather) chair at his (custom-made) desk.

For one hysterical moment, Iruka recalled every last rumour that he'd heard about ANBU — the lauded adoration that poured forth from the people who never managed to land a job there; the post-traumatic invectives of those who had; the universal claims that this boutique investment setup would be the one to drive you — and wondered if he hadn't made the wrong choice moving halfway across the country to join one of the most notoriously well-paying funds in a shattered financial world.

Then he thought about his student loans and the fact that he'd graduated in Mathematics (with honours and ribbons and rainbows coming out of his advisors' recommendation letters, yes, but in _Mathematics_), which is about when Iruka swallowed down the hysteria at the back of his throat and said, 'Where do I start?'

Genma grinned at him, chewing on what looked like the much-mangled remains of a Starbucks stirrer, and went, 'Well, how many times do you want to go home this week?'

* * *

><p>Iruka very quickly learned several things about ANBU. The first thing was that everyone in the fund was insane; Iruka had expected that of investment bankers, and it was only the fourth wall in his head that separated them (well-heeled wannabe superstars) from him (poor starving Mr. Umino, in it only because his maths could win it) that kept Iruka from running away from this gilded world of scary salaries and scarier bonuses.<p>

Second was the fact that they, his co-workers, weren't actually as evil and soulless as Iruka had expected them to be: they worked as late as he did because they liked the challenge, the late-night epiphanies, the unfortunate times when either Izumo or Kotetsu were allowed out of their secretarial-accountants cages to play Taylor Swift very loudly on the office's billion dollar sound system.

A corollary to that was that nobody went home much or went out much, except maybe on weekends, which was when _everyone_ went out, mostly because there was safety in drinking in numbers: statistical probably was that at least one person would be sober enough at the end of the night to deposit everyone else somewhere safe.

'Sarutobi's hiring habits are weird,' Genma'd told Iruka one time as the both of them carefully stacked Prada-clad limbs into the back of taxicabs. 'But hey, you can't complain, the office is fun, right?'

Iruka also learned that you were always there for your co-workers (who were your friends, who were, if you squinted right, your family), and that you ignored the fact that you didn't see your apartment for five days a week.

Most of all, Iruka learned that there were certain lines that you didn't cross: one of them was the third door down the hall. That was the office just before Mr. Sarutobi's, and it was (according to the name plate) inhabited by a HATAKE KAKASHI, and if you disturbed him apparently the world ended for ANBU.

'Kakashi's, well, _special_,' Genma told Iruka when Iruka asked. 'He's got a brain like a steel trap and business instinct that'd make most of the business district cry like babies, so old man Sarutobi lets him do what he wants.'

'Such as, never come to work at all, ever?' Iruka asked, only a little jealous. Just a little.

Genma's smile was pained. 'Kakashi's _around_, he's just unique about... timetabling.'

* * *

><p>'Good morning, gentlemen~'<p>

Every morning around 11.30, when the office would be in the pre-lunch stupor between wakefulness and obliviousness, one of the janitorial staff or whomever would waltz into the office and pick up people's coffee mugs and then disappear and never be seen again. Iruka only noticed him peripherally, usually being preoccupied with thinking up new ways of propping his eyes open with toothpicks.

* * *

><p>The maths, Iruka thought to himself dazedly two months into the job, the <em>maths<em> was brilliant, the maths was amazing, the maths was a wondrous network of crazy things happening in a matrix of real-life greed, numbers banging about and sneaking up on you and obeying the rules of complexity one moment only to decay into simplexity the next. He knew before he'd even begun thinking about graduate schools that he wasn't made for a life in academia, that he'd wanted to go out into the world and do things in it with maths, but Iruka had never imagined in a thousand years that finance could be this _weird_ or this beautiful.

Or this depressing, Iruka acknowledged, because it was two a.m. and everyone was still in the office staring at whole markets crumbling to bits as people scrambled to second guess the second-guessing second guessers and get a quick buck before everything went pear-shaped for real. People were greedy and evil and regulators were in on the game and, if he really wanted to be honest with himself, he was playing the game now too, with all this algorithm munching producing models that helped really rich people get richer.

This particular model that Iruka was working on combined both sides of the equation, balancing it out into a money-making machine that was supported by an invisible and crystalline mathematical framework that was half idiot guesswork and half savant genius. There were so many kinks in it; it had been Iruka's job for the last two weeks to try to work them out. It drew him in like an Escherian staircase, boggling to the eye and impossible to the mind.

'Hey,' Genma appeared at his desk. 'Oi, newbie.' A hand was waved in front of Iruka's face.

'He's going catatonic,' Anko beamed, coming over from her desk (MITARASHI ANKO, RISK). 'I'm pretty impressed that it's taken him this long.'

'I'm okay,' Iruka said faintly, blinking at the lines on his screen. 'Really, just. More coffee, or something.'

'Yeah, well, more coffee and you'll have more caffeine in your bloodstream than platelets. C'mon, shove over,' Genma said, rolling Iruka's chair out of the way to get to his programme. Iruka was too tired to do anything but sort of cling to the armrests in despair.

'The model's not fully optimised yet,' he objected, but not very hard.

'Don't worry,' Anko cooed, coming over to stand behind him. Her fingers sunk into the rock quarry where Iruka's shoulder muscles had once been and _squeezed_. Iruka made several undignified noises to signify that this was the best thing that had happened to him since Naruto, one of their noisy interns, had taken pity on him and begun to buy Iruka takeout so that he didn't have to leave his desk so much for insignificant things like nourishment and sunlight. 'We _know_ it's not optimised.'

'Holy shit,' Genma went from Iruka's desk. '_Holy shit_.'

'Aargh?' went Iruka curiously.

'Hey, Guy!' Genma was yelling, but why was Genma yelling? Iruka wondered. Guy was one of their higher-ups, magically indefatigable and as fearfully bright in person as his clothes were in colour. 'YES, GENMA?' Guy erupted out of his office, fresh as daisies. 'YOU CALLED FOR MY ASSISTANCE?'

'C'mere, Guy, look at this,' Genma jabbered, pointing at the screen. Iruka envisaged that he might've been motioning at that particular section that had been driving him up the wall; whoever'd done the foundational work on the thing must have had a mind that lit up under an EEG like christmas lights. 'Look,' Genma insisted, yanking Guy in. 'Look.'

Guy ran a simulation, paused for a second, and then went, 'Oh ho.'

'Oh, no,' Anko said sympathetically, patting Iruka on the arm.

'It's that bad?' Iruka asked, shaking a little.

'It isn't bad, my dear Mr. Umino,' Guy said, turning the full laser intensity of his beam upon Iruka's burnt out corneas. 'It's _fantastic_.'

'Best I've ever seen anyone do on the Bell Model,' Genma concurred. 'Okay then, this calls for a celebration,' he said, and legged it to the pantry and came back a moment later with a bottle of something expensive-looking in his hand.

'Is that champagne?' Iruka asked weakly as Genma popped the cork and sent bubbly everywhere.

'You bet it,' Anko said, filling up a very big mug of it and put it into Iruka's unresisting hands.

Iruka took a medicinal sip and furrowed his brow. 'What's the occasion?'

'Your death,' Genma mumbled the same time that Guy exclaimed, 'Your promotion!'

* * *

><p>'Hi,' Hatake Kakashi said to Iruka in his office the next day at eleven thirty a.m., but only after he'd waltzed through the office and collected up the coffee mugs and sat in one of the boardrooms reading a book for thirty minutes. He was two hours late, and —<p>

'But you're the janitor!' Iruka protested, eyes boggling. Kakashi had a mop of silver hair and an eyepatch over his eye and dressed in, in, in _something_ that would've made Anko, with her superhighheels and supersharpskirts cry out in pain. Iruka wasn't aware of any kind of fashion standards, but he wasn't _blind_.

'It takes a lot of effort to look poor, you know,' Kakashi protested mildly. 'And do you have something against cleaning staff? Because they do honest work.'

'I, but, you're _late_,' Iruka blabbered, because he had a hangover that Lucifer had apparently reserved specially for people who stayed up drinking the day before they were due to meet their new superior. Who would, as life would have it, turn out to be incredibly tardy and have no apparent sense of personal hygiene in spite of working one of the most desirable jobs in the northern hemisphere.

'I got lost on the road of life, you know how it goes,' Kakashi beamed at him, and pointed Iruka towards the desk on the other side of his office. 'This is your new desk; I took the liberty of helping you decorate.' There were dolphins. Lots of dolphins. Dolphins _everywhere_: on the mousepad, on the computer's background. Iruka held back a scream.

'Excuse me terribly,' he said, voice tightly controlled, 'but I thought I was being promoted, Mr. Hatake.'

'You are!' Kakashi reassured him. 'To my secretary.'

'HOW IS THAT A PROMOTION,' Iruka screamed, and then he realised he'd said at out loud and there were sniggering sounds coming from outside the door. Iruka wanted to melt into the floor and die. He'd never been impolite in the workplace, but ANBU was just so absurd that this, this was the final straw.

'We-ll,' Kakashi tapped his chin, pondering the question. 'You get a nicer computer and better pay, and since you managed to get farther than anyone else has gone on my model, you'll get more interesting projects to work on too. Oh, and I don't care whether you come in at nine in the morning or nine at night, isn't that great?'

'THAT IS NOT GREAT,' Iruka yelled, because yelling was hard to turn off once it came on. 'AND YOUR MODEL ALMOST DROVE ME INSANE.'

'Many mathematicians do turn out that way,' Kakashi agreed mournfully.

'IT HAD SO MANY —' Iruka stopped as the reality of the situation hit him 'You did that?' he asked, shocked into silence. 'All of it was original?'

'Yep,' Kakashi grinned. 'Not my best work, it doesn't do well in too many situations, but they,' there he gestured at the suddenly absent crowd of ANBU employees who had been hovering outside his door, 'find it great fun to inflict on people we're placing.'

'Airigigh,' Iruka managed, before translating that into words. 'I've never seen something so twisted or so elegant.'

'That's somewhat paradoxical, but very nice of you to say,' Kakashi said demurely. 'So, want to try something even more fun?' He waggled his eyebrows, and Iruka was suddenly aware that, underneath Kakashi's slouch and disregard for fashion was a mind sharper than a box of razors and a man who wasn't too bad looking either.

Well, if he was flushing, it was just the mental strain. Ahahaha. But when he said 'Yes,' the fervency in his voice was absolutely real.

* * *

><p>Working for Kakashi, Iruka miserably admitted to himself, was better. Not that ANBU wasn't a stimulating workplace, but Kakashi was on a whole other level. He didn't just work, he <em>thought<em>. He left formulae scribbles on the memos that he inconsiderately littered Iruka's neat-as-a-pin desk with, his integral signs curved into the beautiful arch of a musical clef. For a man who's knowledge of the financial system was encyclopaedic, his office was unusually bare of references: only bits of literature or prosaic mathematics books chucked here and there, alongside a porn collection that Iruka had discovered and screamed mentally at and then hid under a hundred layers of paperwork.

Kakashi played with millions of dollars like they didn't matter to him, wore whatever he picked up off of his wardrobe floor to work, and — surprisingly — was undetectable in the office during normal working hours but was inexplicably present when Iruka stumbled in at six in the morning one Sunday after he'd sent the rabble home but realised he'd left his phone in the office. The expression on Kakashi's face, if Iruka ignored the surprise, had been one of intense concentration: focus and dedication and that quicksilver intelligence that Kakashi never showed the world suddenly all on display before the man had chuckled like a demon and spun his monitor around to proudly exhibit to Iruka the truly offensive piece of fanfiction that he'd been reading.

Kakashi had no sense of Iruka's personal space, but clammed up whenever Iruka asked about his eyepatch. Kakashi draped himself over the back of Iruka's chair whenever they worked through a problem together, and confused Iruka into letting him get away with it by spewing the most terrible and enlightening maths as a distraction. Kakashi couldn't remember when a civil dinner time was supposed to be, but magically made Iruka perfect coffee in the mornings instead of having it be the other way around.

After the first week, Iruka stopped wanting to kill himself, and after the second week, Iruka stopped wanting to kill Kakashi. The rest of the office bought him dinner after that and told him that "no one else has ever survived this long!", as though it was community service, being Kakashi's secretary.

After the third week, Iruka wanted to kill both himself and Kakashi, but the feeling ebbed and flowed with alarming consistency, like the gentle river of a sine curve cutting its way into the future.

* * *

><p>'Kakashi,' Iruka stuck his head into the office at 8p.m. one night, confident in catching the man because this was always when Kakashi chose to have his weekly dose of Korean soap opera projected only the board room screen for his viewing pleasure.<p>

'Eh?' Kakashi responded, eyes glued to the scene being showed, which to Iruka seemed to involve cancer, betrayal, tears, and a small dog.

'I'm going out with a couple of old friends from college tonight, just wanted to know if you would like to tag along,' Iruka offered, accidentally pressing his elbow onto the STOP button on the projector. 'Genma's coming, and you never join us on weekends, so.'

'I'm bad with people,' Kakashi said lazily, eyeing the projector.

'You're bad _to_ people, it's different,' Iruka insisted. 'It'll only be for a little while.'

'No,' Kakashi told him patiently, edging towards the remote control in what he assumed was a stealthy manner. 'I'm genuinely bad with people.'

'There will be girls,' Iruka pointed out.

Kakashi shot him a look.

'There will be guys?' Iruka tried.

Kakashi gave him a filthy grin.

'There will be alcohol and my fist in your groin if you keep looking at me that way,' Iruka growled.

Kakashi dove for the remote, but Iruka was prepared and faster. He held it dangling over Kakashi's head for a moment before snatching it away and shoving it into his pocket. 'Kakashi,' Iruka sighed. 'You've been working on the latest thing for Sarutobi-san for so long that you're beginning to mumble prime numbers in your sleep. It's time to get out a little before you get cabin fever and start losing it. More than you already have, anyway.'

'I'm horrible at groups, Iruka,' Kakashi — was Kakashi _whining?_

Iruka could sometimes be sneaky. He didn't like to use that particular skill set, just in case someone at the office noticed and landed him in a position where he could actually make money and therefore contribute to the general imbalance in overall societal wages (hey, he couldn't be a hero, but he wasn't set up for villainy either). But desperate times called for desperate measures. 'Keep me company?' he wheedled.

'You'd better be prepared to buy me seasons worth of dramas if this goes wrong,' Kakashi warned him.

* * *

><p>'Oh good lord,' Iruka whispered into Genma's ear, staring at Kakashi slouched at the corner of their table. Thus far Kakashi had communicated twice: once to order his drink, and then to say "no" when someone had asked in a roundabout manner if he had a girlfriend. 'Is he always like this?' Now the people at the table wouldn't leave him alone and Kakashi had decided that, in response, he would act as though the world beyond the bottom of his gin and tonic didn't exist.<p>

'Yes,' Genma hissed in reply. 'I don't know how you got him out here, but Kakashi has serious crowd issues.'

'Why?' Iruka asked. 'He wouldn't be so bad if he, you know, opened his mouth and spoke every now and then.'

'It's just that his reputation precedes him,' Genma shrugged helplessly. 'It's all, Hatake Kakashi, millionaire before most people have got over their acne problems! And all that sort of stuff.'

'He was a millionaire _when_?' Iruka gaped at Genma.

'Sixteen or something like that,' Genma said as though it were common knowledge. Which, considering the small crowd around him, it was, apparently. 'Everyone knows,' Genma told Iruka, eyebrows arched high. 'Didn't you?'

'I never really cared about this sort of stuff,' Iruka said weakly. 'My family was so poor that I shared a bedroom with my parents until the embarrassment of it made me move out into the living room. What?' he asked Genma, who was staring.

'How the hell did you end up in this industry?' Genma asked incredulously.

'I like numbers, okay!' Iruka said hotly. 'A lot!' He shot a look at Kakashi, who looked the closest to miserable Iruka'd ever seen him. 'I've got to go save him now, sorry.'

Genma shook his head in disbelief. 'No wonder he likes you.'

'He doesn't _like_ me, he torments me,' Iruka said quickly.

'Yeah, yeah, it's Kakashi, it's the same damn thing,' Genma groused, and ordered another martini so that he could watch as Iruka peeled high society off of his boss.

* * *

><p><em>Three months later<em>

'I'LL KILL YOU,' Iruka yelled at Kakashi's locked office door. '_KILL_ YOU, KAKASHI, IF YOU DON'T OPEN THIS DOOR RIGHT NOW AND COME OUT HERE SO THAT I CAN PUT YOU IN SOMETHING ACCEPTABLE BEFORE OUR VERY IMPORTANT, VERY RICH CLIENT RUNS SCREAMING TO THE AIRPORT AFTER MEETING YOU FOR THE LUNCH THAT YOU'RE SUPPOSED TO BE AT IN _FORTY-FIVE MINUTES._'

'Look at him,' Genma said to Anko as they watched with affection in their eyes. 'All grown up, our baby Iruka.'

'YOU NEVER HAVE LUNCH MEETINGS, KAKASHI, FOR CRYING OUT LOUD. THE REST OF US HAVE TO WINE AND DINE AND SING AND DANCE AND ALL YOU HAVE TO DO IS SHOW UP TO SIGN ONE PIECE OF PAPER AND EAT EXPENSIVE SUSHI,' Iruka continued his tirade.

'Kakashi hates meetings,' Guy told Iruka, drawn out by the screams. 'My esteemed rival is very shy: his heart is a tender lily that shies away from the sun of social interaction.'

'OH, YOU'RE RIGHT, GUY,' Iruka swore, 'BECAUSE KAKASHI WILL BE REALLY _TENDER_ BY THE TIME I'M DONE WITH HIM IF HE MAKES US LATE.'

'I didn't know you cared,' Kakashi volleyed from behind the door, but didn't open it.

'I HATE YOU SO MUCH,' Iruka railed.

'I read in a magazine that that's the flip side of love,' Kakashi sang.

'I'LL QUIT,' Iruka threatened. 'GOLDMAN SACHS' INTERNATIONAL OFFICE HAS BEEN IN TOUCH.'

The door slid open immediately. 'Have they been touching you inappropriately?' Kakashi stepped out and Iruka's next words died in his mouth. 'Because if they have,' said Kakashi, clad in a suit so sharp Iruka'd cut himself on his cuffs, 'I'll have to have words.'

Oh my god, Iruka thought to himself, I wish ANBU had some idea of office etiquette, because then staring at Kakashi would be very wrong and I wouldn't have allowed myself to do it.

'Hehehehehehehehe,' went Anko and Genma, in horrifying unison somewhere behind him.

Iruka coughed and hoped to some merciful god that his face was still straight. 'You, uh, dressed up.'

'Can't embarrass the fund in front of clients, can I,' Kakashi asked, tucking a leather folder underneath his arm. 'Is my tie straight?'

Iruka wanted quite badly to pretend that it wasn't, just so that he could reach out and —. 'Yes,' he said, manfully regaining his sanity in spite of great temptation. 'It's perfect, now come on,' he said, shaking his watch at Kakashi, 'we're going to be late.' He stomped off to call the elevator.

'Hatake,' Genma said with respect in his voice, 'you may just have got yourself a catch.'

'If you don't drive him crazy first,' Anko qualified.

'IS THIS THE SPRINGTIME OF YOUR YOUTH?' Guy asked, sparkling. 'OH, KAKASHI.'

'_HATAKE KAKASHI_,' Iruka roared from the elevator lobby.

Kakashi beamed.

* * *

><p>One multi-bazillionionininon dollar lunch deal later, Iruka came to pick Kakashi up in a company car and did as good a job as he could manage not staring when Kakashi slithered into the passenger seat and slouched the entire way back.<p>

'Was the President there?' Iruka asked, filling the silence with blessed work talk.

'Nope,' Kakashi shook his head, reaching up to drag the knot of his tie down. Iruka may have almost mowed down a bike messenger.

'Uh,' Iruka coughed. 'Is that unusual? I would've thought that clients like that would want someone, you know. High up.'

'Am I not "high up" enough for you?' Kakashi asked, a little amused. 'Well,' he said, reclining his seat and shutting his eyes for a nap. 'I am kind of related to Sarutobi, I guess.'

'What?' Iruka blinked, making a mental note not to talk to Kakashi while driving — it was bloody dangerous.

On my mother's side,' Kakashi nodded absently. 'Aunt's cousin's third daughter's boyfriend's landlord, that sort of thing.'

'I'm going to die before I'm fifty,' Iruka said firmly. 'You're going to kill me.'

'Fifty?' Kakashi mumbled sleepily. 'That long?'

Iruka may or may not have stepped on the brakes rather late the next light because of that. 'Sorry,' he apologised viciously when Kakashi almost slammed his face onto the dashboard.

* * *

><p>Then one day, a man called Yamato came waltzing through ANBU's front door bearing chocolates and cards and good news about $10,000,000 accounts from the overseas office. As Iruka gawked, he talked to everyone as though he'd known them forever, and was fawned over and loved and adored. Anko spent ages straightening Yamato's collar; Genma, lord and master of pocket strings, offered to buy him lunch, and even Shikaku dug out a smile for him from the graveyard where he normally buried his compassion.<p>

Iruka waited, with a sort of inner schadenfreude he hadn't known he'd possessed, for Kakashi to emerge henceforth from his office to bring the hammer of humility down on Yamato's head, but when Kakashi _did_ come out to see what the fuss was about, all that happened was a subtle widening of his eyes and a happy exclamation of 'Tenzo, you're a day early,' before Kakashi comes over to ruffle Yamato's perfect hair and liberate him of Godiva. They disappeared down the elevator ten minutes later, going for food.

Iruka felt an irrational but unquenchable desire to accidentally push Yamato in front of one of the city's ubiquitous and undoubtedly lethal-upon-impact taxi cabs.

* * *

><p>The worst part about it was that Yamato, as it turned out, was a brilliant, wonderful, nice, normal, sane individual. After a week of intensely concentrating on a project in Kakashi's office that did not in any way involve spying on Yamato or sulking, Iruka decided that ANBU had clearly turned him into a mess of mixed up emotions and no social etiquette, and so ventured meekly out into the general office space to make first contact. Yamato had taken over the empty space where Iruka used to sit before his promotion, and upon engagement told Iruka quite happily that he'd once been Kakashi's secretary, too. 'Worst time of my life,' he admitted. 'Best thing to ever happen to my career, though. Kakashi-senpai is frustrating, but you won't find another mind like his in the business.'<p>

Iruka floundered for a while with his inner conscience, then gave up because there was really no reason for jealousy, and even if there was, he was firmly not thinking about it. 'Want to go out for a drink after work and swap stories?' he offered instead, a feeble but sincere olive branch.

'I didn't know that about him, but after Genma — hiccup — told me about the whole, well, genius millionaire thing, it all started to make sense. It's _Kakashi_. He can't find his ass with a torchlight, but he probably knows Dolce _and_ Banana,' Iruka moaned into his drink as Yamato poured him another one. 'Whoever they are!'

'It's Dolce and Gabbana,' Yamato corrected him helpfully.

'Yeah!' Iruka agreed fiercely. 'Them! And then he just messes with me when I ask him real questions. He told me he was related to Sarutobi-san, _hah_!'

'But he is,' Yamato said patiently.

'Eh?' Iruka spluttered. 'By his mother's cousin's dog?'

'No,' Yamato said slowly, staring at Iruka like he was stupid, which Iruka felt right then, alongside being drunk, and stuff. 'He got his first, well, real job through Namikaze, who was a personal friend of the family and long-time tutor, apparently. And Namikaze — Iruka-san!' Yamato said in alarm as Iruka's fingers found themselves in his lapels.

'The Namikaze?' Iruka demanded, shaking Yamato a little harder than he should have. 'Namikaze Minato, the mathematician?'

'Yes?' Yamato said, holding his hands up in surrender. A light dawned. 'Oh, so you're the mathematician that Kakashi-senpai kept emailing me about! Ha ha, sorry, he doesn't do very well at connecting certain things, and he just had so many good things to say that I didn't imagine it could've been someone in finance — Iruka-san? Are you all right?'

'Aaaaaagh,' Iruka said simply, slumping onto the bar counter. 'Aaaaagh.'

* * *

><p>When Iruka woke up he wasn't sure if it was night or day or whether he was alive or dead, because whatever he was laying on was absurdly comfortable and could not, therefore, be his own bed. He moved, which proved to be an extremely bad idea: a colony of miners promptly got to work digging out the remnants of his brain from the cavity that was his aching skull.<p>

'I wouldn't do that, if I were you,' Kakashi's voice floated over. 'Tenzo told me that you'd got yourself through quite an impressive number of drinks before you passed out.'

'Am I dreaming?' Iruka asked what must ostensibly have been Kakashi's ceiling. The room was dark and cool; the bed was big and comfortable and covered with sheets that had a thread-count beyond any whole number Iruka could think of. 'I must be dreaming.'

Kakashi threw open the curtains. Iruka howled, 'I'm not dreaming, I'm not dreaming, shut them, please!'

Pills pressed themselves into his hand, and then a glass of water. 'Drink,' Kakashi told him, and Iruka gladly chased the painkillers down without objection. 'Thank you,' he managed hoarsely a few minutes later when he felt evolved enough to call himself human again.

'No problem,' Kakashi said, taking the glass out of Iruka's hand. He sounded amused instead of bothered. 'I called us both in.'

'Arghh,' Iruka went, peeling his unwilling eyelids open. 'It's a workday?'

'Yes?' Kakashi went, as though missing work at ANBU was something anyone could do at any time without life-ending consequences. Iruka had seen what Shikaku did to Genma that one time back when Genma's come in half a day late without prior leave-taking. They had to scrape Genma together and bribe him with Starbucks before he stopped whimpering.

'I'm going to die,' Iruka said with finality, throwing an arm over his eyes. 'Shikaku is going to tear me to pieces and then feed me to the birds and did you say you called us _both_ in?' Iruka shot upright in _Kakashi's bed_ and his hangover could hurt him all it wanted to, but only after the giant blinding panic had passed. 'I'm _going to die_,' Iruka moaned. 'They're _all_ going to tear me to pieces.'

'Is the idea of them connecting the dots together that traumatic? You already know me by my workings and you haven't run away screaming and Genma tells me you didn't even know about all the other irrelevant things. Sarutobi-sensei thinks you're the best influence on me since Tenzo. Who, by the way, hates maths.' Kakashi was laughing, _laughing_, the bastard, because he didn't have a reputation to maintain and he didn't care at all and he was Iruka's boss, technically, and was confusing and infuriating and insane.

Iruka settled for turning to glare at Kakashi. 'Oh,' he said, going quiet. 'Your left eye.' Iruka reached up before he could stop himself.

Kakashi didn't turn his head away. The patch was off, as it never was.

'Heterochromia?' Iruka inquired softly, letting his fingertips brush the edge of Kakashi's cheekbone just underneath his eye. It was a startling brown, almost red. 'It's striking.'

'Too striking,' Kakashi said, shrugging. 'One more thing on the list of things that people check off when they spot me in public.'

'You shouldn't have to hide it,' Iruka told him.

Kakashi raised his right hand and touched the inside of Iruka's wrist. 'No,' he agreed softly. 'But I want to hide it.'

'Why?' Iruka asked, feeling like this was a conversation he couldn't just run away from, like this was _important_. 'Because it's rare?'

'It occurs in about 1% of the population,' Kakashi said, easily reciting the statistic. He trailed a finger down Iruka's wrist, resting his hand on the juncture of Iruka's elbow. 'Do you want to know what that is in numbers?'

'I always want to hear you talk about numbers,' Iruka said, opening his palm and laying it warm across Kakashi's bare cheek. 'I love it when you talk about numbers.'

* * *

><p>Iruka had just finished begging Shikaku for mercy when Kakashi waltzed in at eleven thirty, dressed in something woefully threadbare, and sang, 'Iruka! I need you in my office to help me factorise some primes.'<p>

'Factorise primes? Is that even possible?' Yamato asked Genma, puzzled. 'That's not possible.' Yamato's eyes widened. 'That's impossible!'

'Kakashi,' Shikaku said wearily, 'Not that I'm unhappy to see that you're finally showing signs of being human, but allow me to define the world "office-mate" for you: it's a noun. Not a verb.'

Iruka put his face in his hands, and counted the numbers in his head, one all the way up to ten.

'KAKASHI!'


End file.
